Outdoor light-emitting diode (LED) signs are known for various purposes, such as for traffic signage, advertisement billboards, outdoor sporting events, etc. Outdoor LED signs have many challenges, such as ruggedization to withstand outdoor environmental conditions (e.g., wind, rain, dust/debris, and other weather and temperature conditions), power requirements and heat dissipation for the multitude of LEDs required to display outdoor viewable messages and content, accessibility to internal components for maintenance purposes, brilliance and contrast in the LED pixels, and costs associated with manufacturing such often large structures, to name a few.
Often, improvements in one area will result in drawbacks associated with another area. For example, one problem with outdoor LED signs is increasing the brilliance and contrast of the LED pixels, while not also increasing power consumption of the LED sign and heat generation. Further, increased power consumption and heat generation will often result in the need to construct heavier, more complicated systems, which in-turn increases manufacturing costs. U.S. Pat. No. 6,169,632 (Kurtenbach et al.) attempted to at least solve some of these problems by creating a modular display system in which each modular display panel included a circuit board with various LED pixels mounted in a housing. Further, the modular display panels in Kurtenbach et al. includes louver panels interspersed with the LED pixels to shade the LED pixels from ambient light, thereby improving the view contrast and viewability. In addition, each modular display panel in Kurtenbach et al. is secured to one or more modular support members by quick connect latches and includes a driver board and a power supply securable to the modular display by twist-on fasteners. Accessibility is provided on both sides of the Kurtenbach et al. display system through the quick connect latches and ready removability of the circuit boards and louver panels.
Unfortunately, the modular display system in Kurtenback et al. suffered from at least one major drawback. For outdoor LED signs, there is a problem of high wind resistance due to their solid surfaces and their considerable size, which is often required in order for the LED pixels to be visible from long distances. Further, outdoor LED signs are often placed at higher altitudes for greater visibility, which increases the wind resistance even more because wind resistance tends to increase at higher altitudes.
U.S. Pat. No. 7,407,306 (DeMarb et al.) addressed this problem by providing an aerodynamic display panel with a plurality of stacked layers wings with space between the layers to allow air, rain, and other elements to pass through. Unfortunately, the DeMarb et al. aerodynamic display panel suffers from a multitude of drawbacks. Initially, the layers have a wing-shaped cross-section which, as wind flows through the wing layers, results in a lifting force caused by the pressure difference above the wing as compared to the pressure below the wing. Accordingly, such lifting forces will create a strain on the aerodynamic display panel. In addition, the risk of wind forces knocking down the display panel of DeMarb et al. is increased as a result of both horizontal wind forces and vertical lifting forces acting on the display panel simultaneously. In addition, each layer in DeMarb et al. is a separate enclosure for an LED to provide protection to the electrical components from environmental hazards. Unfortunately, such design results in a rather complicated and difficult to assemble and manufacture display panel including horizontal support receivers and vertical support receivers built into each layer and corresponding vertical and horizontal support beams to be routed through such receivers in order to assemble the display and support the layer enclosures thereon. Accordingly, the manufacturing and assembling the DeMarb et al. aerodynamic display panel would be rather costly and time-consuming. Furthermore, the DeMarb et al. aerodynamic display panel is not readily accessible for maintenance purposes. If even one of the layers requirement repair or replacement, it would be rather time consuming to disassemble the display panel in order to perform the repair or replacement. Also, it would be difficult to selectively program the DeMarb et al. sign to display varying messages and/or content on-the-fly as each layer is a separate enclosure shielding its electrical components from environmental hazards.
Therefore, a need exists to overcome the problems with the prior art as discussed above.